I agree with Melissa, ask your doctor. But it would not hurt to go in with some ideas to ask about!

How about water aerobics? Its low impact, and no stress on joints. The resistance of the water makes it a really good workout. I 'water jog' for exercise frequently, and I check my blood sugar levels before and after. It is as effective as walking for lowering my glucose level, which tells me it is good at burning calories. Can you do any weight lifting? Strengthening and toning muscle helps burn more calories.